Strong opinions, but you should never take what any one person says as gospel.

There are as many ways to write as there are authors

Please just just use “said” and “asked”. Reuse them. They are invisible to the reader. Don’t be creative.

“Matt”, she said, careful eyes on me, “is eighteen now.”

By putting the “careful eyes on me” where it is, it sets up the reader for what follows. It casts a shadow on the dialogue that follows.

“careful eyes on me” is the narrator giving information without telling, and gives us insight into the feelings of a character other than the point of view character.

em dash vs. ellipsis: em dash is changing the characters thought. the ellipsis is a pause in the characters speech, or trailed off if at the end of dialogue. If there’s an em dash at the end of dialogue, it means something that happened before the dialogue was finished.

Then you don’t have to say “he interrupted”, because the em dash told the reader.

Usually in a scene it is fun to be in the head of the character who is more off balance.